The Week Junior - Science + Nature
Satellites get new view of Arctic sea ice
Artificial intelligence helps scientists monitor changing sea-ice levels.
Satellites will now be able to measure the thickness of sea ice in the Arctic Ocean all year round. This will help scientists keep a closer check on sea-ice melting, and predict the real effects of Earth’s changing climate.
The European Space Agency’s Cryosat-2 mission measures the thickness of ice in the polar Arctic Ocean. The satellite can detect the height difference between the top of the ice and the water surface in the cracks separating ice sheets, or floes. It beams a pulse of microwaves (a type of light energy) towards the surface. When the energy hits ice or water, reflections bounce back to the satellite, allowing scientists to calculate how high the ice is above the water. However, in summer, pools of melted water on top of the floes confuse the radar because they can look like the ocean surface. This means that between May and September – the key period of ice melting – results from Cryosat-2 have been unreliable.
To get around this problem, Dr Jack Landy and his colleagues from The Arctic University of Norway have used an artificial intelligence (AI) system to train the radar to know the difference between open ocean and meltwater. AI is a computer system that can do things that usually require human intelligence. The researchers have been able to go back through the years, and calculate how the thickness and cover of sea ice has changed over time.
Due to climate change (the long-term changes in world weather caused mainly by human activities), scientists think that the Arctic Ocean is headed for ice-free summers. This will affect many animals, such as polar bears and walruses, as well as people who live in the region. However, predictions of when this might happen are quite inaccurate. “We need to tighten those predictions so we’re a lot more confident about what’s going to happen and when,” Dr Landy told BBC News. This new information could help scientists better prepare for, or even prevent, the worst consequences of climate change.